hope any other 2L owners dont find there cat broken because your going to be looking at over £200 for supply and fit managed to get the cheapest quote of £150 supplied and fitted from my usual garage i go to

I guess if you went to the hassle of only fitting the cat at MOT time it'd last forever.

was thinking of getting a decat pipe but didnt know if you could buy them

Yeah you sure can.
Where's Robley and co....?

eh? you just cut it off and replace with a suitable sized pipe.

or you could go a step further - take the cat off, split it in half, take everything out
and replace with a suitable sized pipe, weld it all back together and onto the car
and then it will look like you still have a cat.

p.s. lambda sensor has nothing to do with cat directly, you need it for the ECU,
so make sure you leave it where it is.

But what happens at MOT time?

You give the MOT guy a few of the notes from the £150 you have in your pocket from not buying a new cat?

Ah but is that possible with the new stylee MOT? I heard the emissions testing stuff is all connected up to a main computer..... or maybe I'm wrong.
Actually they could always stick the exhaust gas analyser probe in the tail pipe of another car.

While we're on the subject has anyone ever done a "before and after" test on a rolling road when removing their cat?

A local dyno tune firm in Australia did flow and power tests on an s15 silvia (SR20DET), with a cat and and the de-cat pipe: there is no improvement in power with a straight pipe in place.

The only thing you will gain with a de-cat pipe in Australia is a AUD$5000 fine from the Environment Protection Agency

I assume this is the same case with England and Europe?

However, I would like to know if anyone has the flow rating (in CFM) for a std Mi16 cat?

I got my "sports"cat (metallic monolith) with custom pipes in both ends (to fit downpipe and 2.5" after cat) for around 125£ and in sweden its 25% VAT included in that sum.

The metallic monolith is better to withstand both missfires and physical punishment than the cheramic dito.

Personal I'm against all versions of "de-cat" pipes.

You could also use a cat from another car, such as one from a 6 cylinder. Should provide decent flow and be pretty close to the diameters of the original pipe (new cat convertor of course).

cat now replaced and boy what a difrence it makes new cat seems smaller than old one though?

a difference in what way???

old cat was blocking up and the conection was blowing so its all how it should be now